I recently built a class D dual mono amp from (2) Icepower 1200AS mono amps. It's my first experience with class D. I went from an Adcom 5802 to this. They couldn't be further from each other in sound. The Adcom 5802 was all weight and overly fleshed out and a little on the dark side with my 12" + 15" combo and the Icepower is big fast and light. Almost too thin and quick. I was watching Paul McGowan's, from PS audio, recent video on "Stereo vs Mono amps" and he was showing off their input stage (w/ tube) for the exact same module that I have. He said that it "was where the magic happens" with their amp. I want to bring back some of the weight and flesh out the bass a little more than what the 1200AS is doing. I don't want to copy/steal what PS Audio has but is there something along those lines out there? It doesn't really have to have a tube. I'm more interested in sound but a tube is fine too. Thanks
Well, looking at what ps audio does they have both bal. and unbalanced inputs... Bottom line I only need balanced inputs with little to no gain. Keeping the circuit balanced or SE is the question... I’m out of my depth here. I throw it out to all, what do you think? If it is with a tube could it remain balanced?
Some gain is ok but I would prefer to keep the overall gain of the amp as low as poss. But if it means adding some gain to get the sound I’m after I’ll do it. I can always pad it down..
Some gain is ok but I would prefer to keep the overall gain of the amp as low as poss. But if it means adding some gain to get the sound I’m after I’ll do it. I can always pad it down..
Balanced with a tube and no gain is not a problem. I use often a 5670/2c51/6n3/we396 type cathode follower buffer to ad 0,02% second order harmonics to class d amps. That is what ps audio also does. Do you need only schematic or also a PCB design gerber?
You can also modify the schematic for use with 6n6p or ecc99.
You can also modify the schematic for use with 6n6p or ecc99.
Attachments
Last edited:
Below the schematic for the balanced tube buffer(no gain).
It has schematic for silent power supply to. For stand alone.
It has also 20sec startup muting so the tube can heat up without nasty sounds at buffer output.
You can also modify schematic for use with Hypexsmps1200 power supply. Just ask me.
I use it with Hypex class D modules to make them less analytic. Also i use a version with gain for Ncore500 and 1et400a.
Rolling different tubes changes the sound signature a little bit.
Ronny
It has schematic for silent power supply to. For stand alone.
It has also 20sec startup muting so the tube can heat up without nasty sounds at buffer output.
You can also modify schematic for use with Hypexsmps1200 power supply. Just ask me.
I use it with Hypex class D modules to make them less analytic. Also i use a version with gain for Ncore500 and 1et400a.
Rolling different tubes changes the sound signature a little bit.
Ronny
Attachments
Last edited:
I am working on a similar project, it would be very nice to have a Buffer powered directly from the 1200AS2 board.
This amplifier has auxiliary power rails of +15/0/-15, and +60/0/-60.
It would be nice to avoid the inclusion of a transformer on the chassis itself.
You may not need a symmetrical version, a single-ended one would be sufficient, if necessary a balancer circuit can be used later.
Regards
@koifarm, I found a post of yours that says this:
"It is not necessary to convert to symmetrical output. There is no improvement.
Just go asymmetrical with one tubestage and without the opamps. A Ecc99(6n6p) with 6k8 output resistor creates just 3x gain and the right harmonics. Using +/- 65v rail voltage for anode supply and 12v for heater from the original power supply. See picture of my board."
Help with tube buffer
I had a buffer with ECC99, it sounded wonderful, if I could incorporate this buffer into my amp it would be ideal.
Thanks.
"It is not necessary to convert to symmetrical output. There is no improvement.
Just go asymmetrical with one tubestage and without the opamps. A Ecc99(6n6p) with 6k8 output resistor creates just 3x gain and the right harmonics. Using +/- 65v rail voltage for anode supply and 12v for heater from the original power supply. See picture of my board."
Help with tube buffer
I had a buffer with ECC99, it sounded wonderful, if I could incorporate this buffer into my amp it would be ideal.
Thanks.